Four years after the launch of inSPOT.org, which allows people with sexually transmitted diseases to notify sexual partners via email, nearly 50,000 e-cards have been sent, according to an article published in PLoS Medicine.

The site is designed to increase the notification of partners -- part of an overall strategy to prevent and control sexually transmitted diseases. In the U.S. there are 19 million new cases of sexually transmitted diseases diagnosed each year, including 900,000 cases of chlamydia, 330,000 cases of gonorrhea, and 55,400 HIV infections, according to the PLoS Medicine article.

In 2004, the San Francisco Department of Public Health and the Internet Sexuality Information Services conducted research on gay men and men who have sex with men. Researchers concluded that while men are likely to tell their primary partners about diagnoses, they are not as likely to inform casual partners.

The study showed that men overwhelmingly said they would inform casual partners if there were a convenient and anonymous way to do so. The San Francisco Department of Public Health and the Internet Sexuality Information Services then partnered to launch inSPOT. It has since been expanded to other parts of the country and now targets heterosexuals as well.

The email service of inSPOT allows users to choose whether they want to include their own email addresses or not. E-cards include links to information about where and how to get tested. So far, more than 30,000 people have sent over 49,500 cards. In 2007, 28.5% of recipients clicked through the link for testing information.